Refractory furnace

ABSTRACT

A refractory furnace having a cover resting on supports outside the furnace and sealed by an air curtain, in which the peripheral duct in the cover frame supplying the air curtain is fed through the support means from a remote source of pressurized air.

United States Patent 1 91 [111 3,787,172

Sanderson Jan. 22, 1974 REFRACTORY FURNACE 2,407,047 9/1946 West 110/173 A x 3,160,404 12/1964 Potenzo et al. 34/242 [76] Invent g ;:g% yg$:' g 53 53? 3,437',326 4/1969 Augustine et a1 432/250 [22] Filed: Apr. 2, 1973 [21] Appl NO 346 954 7 Primary Exam i z er John J. Camby [30] Foreign Application Priority Data [57] ABSTRACT 7 May 11, 1972 Canada 141864 A refractory furnace ha ing a cover resting on p ports outside the furnace and sealed by an air curtain, 432/250 in which the peripheral duct in the cover frame sup- [58] Field of Search 1 10/173 249 250 plying the air curtain is fed through the support means 3 a from a remote source of pressurized air.

[56] References Cited 5 Claims, 4 Drawing Figures UNITED STATES PATENTS Hubbard 432/247 X REFRACTORY FURNACE The present invention relates to a refractory furnace of the type using a cover or lid.

In certain large refractory furnaces, such as those used for heating steel ingots for rolling, the furnace chamber is closed by a top cover or lid. The refractory material of the cover must be held in a steel frame but the frame cannot rest directly on the walls of the furnace because it would deform. For this reason the cover is constructed to rest on corner pillars outside the refractory walls of the furnace and to carry a downwardly projecting peripheral knife-edge steel rim which locates in a longitudinal groove in the upper edge of the walls, the groove being filled with sand to protect the steel rim from the heat. This construction is unsatisfactory because the sand tends to blow out of the grooves even under slight above-normal air pressure within the furnace. To overcome this problem the steel rim has been replaced in some furnaces by an air curtain projected downwardly around the rim of the cover from a perforated pipe circumscribing the cover. This again has a disadvantage that, in a battery of such furnaces, each cover must carry its own blower mechanism for supplying pressurized air.

It is an object of the present invention to provide a refractory furnace, using a cover having an air curtain seal, in which the pressurized air for the curtain is supplied from a remote source.

An example embodiment of the invention is shown in the accompanying drawings in which:

FIG. 1 is a perspective view of the upper portion of a refractory furnace with cover;

FIG. 2 is a perspective view, partly broken away, showing one upper corner of the furnace of FIG. 1;

FIG. 3 is an exploded perspective view of the cooperating pillar and cover fittings for the furnace of FIG. I; and

FIG. 4 is a view in cross-section taken along line 44 of FIG. I.

The embodiment shown in the drawings consists of a refractory furnace 10 comprising a refractory wall 12 enclosing an upwardly opening chamber I4 with a circumscribing, upwardly facing rim I6 which is flush with a deck I8. Chamber I4 is closed by a cover 20.

Cover 20 of refractory furnace I has a steel frame 22 which carries a refractory lining 24. A pair of parallel beams 26, one at each side of frame 22, are extended at each end to provide bearing means 28. A duct 30 circumscribes cover 20 on the underside of the cover facing rim I6 of refractory wall 12. Duct 30 is perforated throughout its length to provide a continuous row of apertures 32 facing rim 16. Each bearing means 28 has an inlet duct 34 opening from the underside of the foot and connecting with duct 30. As seen in FIG. 4 of the drawings, a divider baffle 36 is fixed in duct 30 facing duct 34. The underside of each bearing means 28 carries a foot 38 framing a vertical passage 40 and having an inverted trough 42 at its lower end.

Trough 42 of foot 38 is constructed to nest on the upper ridge 44 of a pedestal 46 also having a vertical passage 48 which connects with passage 40 in foot 38. A gasket 50, fixed by bolts 52 to pedestal 46, is interposed between trough 42 of foot 38 and ridge 44 of the pedestal.

Each pedestal 46 is fixed by bolts 54 to a fixed base such as a pair of spaced, back-to-back I-beams 56 in deck 18. An air duct 58 leading from a remote source of pressurized air (not shown) branches into lateral ducts 60 beneath deck 18 which connect with pedestals 46 and lead into passages 48 of the pedestals.

In the operation of the described embodiment, chamber 14 of refractory furnace I0 is charged and cover 20 is moved over the furnace by suitable means such as a rail carriage straddling the cover. When cover 20 has been located above furnace I0 it is lowered to have troughs 42 of feet 38 nest with ridge 44 of pedestal 46, with gasket 50 between the trough and the ridge. To provide the seal for cover 20, air is forced continuously through duct 58 to pass through each duct 60 and connected passages 48 and 40 to inlet duct 34 and perforated duct 30 where it emerges under pressure from apertures 32 to form an air curtain 62 directed against rim 16 of refractory wall I2.

I claim:

I. A refractory furnace comprising:

a refractory wall enclosing an upwardly opening chamber,

support means located outside the refractory wall,

the support means having at least one passage connectable with a remote source of pressurized air and opening from the top portion of the support means,

an overhead cover for the chamber comprising a frame carrying refractory material and having bearing means, a peripheral duct fixed to the frame and having an inlet opening from at least one bearing portion of the frame and having air curtain outlet apertures opening towards the refractory wall, the bearing means being constructed and arranged to rest on the support means with the inlet opening of the peripheral duct registering with the passage of the support means.

2. A refractory furnace as claimed in claim 1 in which the support means comprises a plurality of pedestals and the bearing means comprises a plurality of foot means extending from the frame of the cover.

3. A refractory furnace as claimed in claim 2 in which each foot means carries an inverted trough and each pedestal carries a ridge to nest in the trough.

4. A refractory furnace as claimed in claim I including baffle means located in the peripheral duct adjacent the inlet opening thereof and positioned to direct incoming air in different directions along the duct.

5. A refractory furnace as claimed in claim 3 in which the refractory chamber and the cover frame are rectangular, and the cover frame includes two parallel beams at each of two opposed sides thereof, the beams extending at each of their ends beyond the refractory wall to form said foot means. 

1. A refractory furnace comprising: a refractory wall enclosing an upwardly opening chamber, support means located outside the refractory wall, the support means having at least one passage connectable with a remote source of pressurized air and opening from the top portion of the support means, an overhead cover for the chamber comprising a frame carrying refractory material and having bearing means, a peripheral duct fixed to the frame and having an inlet opening from at least one bearing portion of the frame and having air curtain outlet apertures opening towards the refractory wall, the bearing means being constructed and arranged to rest on the support means with the inlet opening of the peripheral duct registering with the passage of the support means.
 2. A refractory furnace as claimed in claim 1 in which the support means comprises a plurality of pedestals and the bearing means comprises a plurality of foot means extending from the frame of the cover.
 3. A refractory furnace as claimed in claim 2 in which each foot means carries an inverted trough and each pedestal carries a ridge to nest in the trough.
 4. A refractory furnace as claimed in claim 1 including baffle means located in the peripheral duct adjacent the inlet opening thereof and positioned to direct incoming air in different directions along the duct.
 5. A refractory furnace as claimed in claim 3 in which the refractory chamber and the cover frame are rectangular, and the cover frame includes two parallel beams at each of two opposed sides thereof, the beams extending at each of their ends beyond the refractory wall to form said foot means. 